I have seen several coments in other posts about battery fans and battery temperature management on the I-MiEV. It's not clear in the sales literature or listening to videos from Mitsubishi engineers but I-MiEV's do not have any traction battery fan unless you have one of the two options---either the battery warming system or the quick charge port. The fan isn't used for any battery temperature management except in very cold temperatures (warming system or quick charge option) or during quick charge (cooling via A/C operation). If you have either option, you will hear the fan start for a few seconds each time you plug in the EVSE. This is to clear the filter on the top of the battery pack. There is no temperature management during normal operation of any I-MiEV. These two optional systems only operate when the battery is being charged, not when driving. I-MiEV's without these options have no place for air to enter the pack and no ductwork inside the pack to distribute any air. There is a small vent on top of the pack but other then that, the pack is sealed. The pack is at the mercy of the outside temperatures just like a LEAF. Mitsubishi really missed the boat on this one as all the component parts are there to make a decent TMS but they never did it.

Are you basing this on the fact that you can hear a fan when you plug in a ChaDeMo equipped car and you can't when you plug in an 'ordinary car'? . . . . or do you have some documentation which says the rest of the cars do not have an air cooled battery? If so, give us a link or two please

All the literature for the 'standard' car (without ChaDeMo or the cold weather package) that I have seen advertise that they all have air cooled battery packs

A BETTER BATTERY BY DESIGN

For over 40 years, Mitsubishi has been leading the charge in electric vehicle innovation, and the i-MiEV is the culmination of all their pioneering work. The custom made Lithium-ion battery packs are safely mounted to the RISE-chassis body, feature two cooling systems and are warrantied for 8 years or 100,000 miles. The time for a better electric car battery is now, and you can find it under the i-MiEV.

This advertisement says that only the ChaDeMo equipped cars have A/C ducted through the battery (one system) but it sure sounds like EVERY car has the other system where a fan which pulls air through the battery

TWO LITHIUM-ION COOLING SYSTEMS

The custom-made battery pack on the ES trim of the i-MiEV features a fan-driven, forced-air induction system that automatically engages to protect the battery from overheating during charging. Drivers can upgrade to the Premium Package, which also gives drivers the ability to charge the i-MiEV using public quick-chargers. Because quick-chargers can tend to heat batteries and reduce their efficiency in the long term, we've added an air-cooling system that draws cold air from the air conditioning unit to keep the battery nice and cool, even in hot climates.

And another mention of the cooling system

OUR EV BATTERY IS ALL MITSUBISHI

While some electric vehicles adapt third-party battery technology, ours is Mitsubishi all the way. To ensure world-class performance, we initiated a joint venture called Lithium Energy Japan to engineer a high-performance lithium-ion electric car battery specifically for the i-MiEV. The result is our custom 16 kWh battery pack that delivers everything you need: a long air-cooled life, responsive power, fast charging and great range. Thanks to our advanced electric car technology, we can back our battery with an 8-year/100,000-mile limited warranty.

Even Wickipedia says it's air cooled . . . . and Air Conditioned *if* you have the ChaDeMo

BATTERY

The 16-kilowatt-hour (58 MJ) lithium-ion battery pack consists of 88 cells placed under the base floor. The pack has 22 cell modules connected in series at a nominal voltage of 330 V. There are two 4-cell modules placed vertically at the center of the pack and ten 8-cell modules placed horizontally. Developed by Mitsubishi and GS Yuasa for both high specific energy and high rate discharge and manufactured by Lithium Energy Japan, a joint venture of GS Yuasa Corporation, Mitsubishi Corporation and Mitsubishi Motors Corporation. The entire pack has a specific energy of 80 Wh/kg. The battery has a forced air cooling system to prevent overheating during high charge and discharge rates and consequent damage. There is an integral fan in the battery pack. For rapid charging, the battery pack is additionally cooled with refrigerated air from the cars air conditioning system.

None of that is correct. It applies only if you have the optional quick charge port or warming system and as I mentioned it is only active under certain conditions when charging. I have two I-MiEV's---one with the battery warming system, the other without. Both are SE's. If you take the motor room cover off and look at the top rear of the battery pack you will see the fan connector and wire on the car with the warming system. The other car has only a rubber plug to fill the hole where the wire would go----no fan. Looking at the center console on the drivers side where the heater duct exits, you will see a actuator mounted on the duct to divert air into the pack on the car with the warming system. There is no such duct on the other car or the actuator. Looking under the car with a flashlight, you can see where the duct from the heater connects to the battery pack through a rubber connector. There is no such connector on the car without the warming system. As I said before, if you have a car without those options there is no airflow in or around the battery. If you want to dig deeper, go to your dealership and look at the salesmans training information for the I-MiEV--it spells it out quite clearly. In addition I have the service manuals and the technical information manual for the I-MiEV which also lays out what is in the car and what is not. The optional systems are the same in design with the warming system turning the heater on prior to charging in -4F temperatures and directing heated air into the pack to raise the temperature before starting the charge. If you have the QC port, in addition to the warming function, the system can be used to use the car's A/C system to cool the battery if the temperature exceeds 86F during the charge. The system never operates except in those to modes---in fact it cannot. Even when you hear the fan running for a few seconds when you plug in the EVSE there is limited airflow to the pack as the damper door by the heater is sealed. It only opens when requested during warming or QC cooling.

I was really unhappy with this as I live in a warm climate. I leased the original I-MiEV and when I found it had a cooling system (that could be easily modified to make it work all the time) I tried to buy out the lease. However, the residual was stupid money so I bought a second car. To my suprise, the other car did not have either option, therefore no fans, ducts, acutators, etc. I went back to the dealer who also thought all I-MiEV's had some kind of airflow system in the battery pack---non of their remaining cars had either option so I was stuck with what I have. What's really stupid about this whole thing is The warming option is only $175.00

Don, after re-reading your reply to my post, I should have said only the parts that allude to all cars having some form of battery temperature control is inaccurate. In fact, even the Nissan LEAF has a "air cooled" battery. The fact that the cooling is by convection into a closed compartment is how it is "cooled" it is still air cooled. A black crowbar laying in the summer sun is air cooled by the heat radiating into the air. It's just something you might not want to pick up without gloves on. Unlike our cars the LEAF at least has a air gap between the individual cells in the modules. In the I-MiEV the cells have no place for airflow around them in except the top, bottom and sides of the four or eight cell modules. Our only hope is that our battery chemistry is a little more tolerant of high temperatures then the LEAF battery. I think we haven't seen a problem with the I-MiEV for a couple of reasons. First the older LEAF's are the ones showing the problems---there's an extra summer on the LEAF's then on the I-MiEV's in our country. Second, there is a smaller sampling of I-MiEV's then LEAF's. Third, the LEAF has a dash display that shows the battery degradation to the driver---There is no such display on the I-MiEV. Many LEAF owners had no idea that there batteries had deteiorated until they lost a bar on the display even though they had lost nearly 20% of the total pack capacity. I would like to hear from any forum members from Phoenix about how their I-MiEV's are doing. Again, I stand by the fact that most I-MiEV's have no cooling of the battery other then convection and no I-MiEV's have way form of controlling battery temperature except when QC'ing (cooling) or pre-charging (heating). The fan etc. will not operate when the car is in the ready mode or being driven.

siai47 wrote:None of that is correct. It applies only if you have the optional quick charge port or warming system and as I mentioned it is only active under certain conditions when charging. I have two I-MiEV's---one with the battery warming system, the other without. Both are SE's. If you take the motor room cover off and look at the top rear of the battery pack you will see the fan connector and wire on the car with the warming system. The other car has only a rubber plug to fill the hole where the wire would go----no fan. Looking at the center console on the drivers side where the heater duct exits, you will see a actuator mounted on the duct to divert air into the pack on the car with the warming system. There is no such duct on the other car or the actuator. Looking under the car with a flashlight, you can see where the duct from the heater connects to the battery pack through a rubber connector. There is no such connector on the car without the warming system. As I said before, if you have a car without those options there is no airflow in or around the battery. If you want to dig deeper, go to your dealership and look at the salesmans training information for the I-MiEV--it spells it out quite clearly. In addition I have the service manuals and the technical information manual for the I-MiEV which also lays out what is in the car and what is not. The optional systems are the same in design with the warming system turning the heater on prior to charging in -4F temperatures and directing heated air into the pack to raise the temperature before starting the charge. If you have the QC port, in addition to the warming function, the system can be used to use the car's A/C system to cool the battery if the temperature exceeds 86F during the charge. The system never operates except in those to modes---in fact it cannot. Even when you hear the fan running for a few seconds when you plug in the EVSE there is limited airflow to the pack as the damper door by the heater is sealed. It only opens when requested during warming or QC cooling.

I was really unhappy with this as I live in a warm climate. I leased the original I-MiEV and when I found it had a cooling system (that could be easily modified to make it work all the time) I tried to buy out the lease. However, the residual was stupid money so I bought a second car. To my suprise, the other car did not have either option, therefore no fans, ducts, acutators, etc. I went back to the dealer who also thought all I-MiEV's had some kind of airflow system in the battery pack---non of their remaining cars had either option so I was stuck with what I have. What's really stupid about this whole thing is The warming option is only $175.00

You are bumming me out. You're right, but you are still bumming me out.I have learned the hard way that the Mitsubishi dealers, including sales people and mechanics, know very little about the i-MiEV. I was told by the dealer that the DC Quick Charge option could be added. Wrong.I could understand the lack of knowledge at the dealer since the electric vehicle is like nothing they have ever seen, but what really surprises me is the wrong information about the battery cooling on the Mitsubishi website.

But how would you air cool a battery when it is 100 degrees out?If your i-MiEV is parked in the sun, then the inside temperature of the car is probably over 100 degrees.You wouldn't want to use that air to try to cool the battery.You wouldn't want to use the outside 100 degree air to cool the battery either.The only option would be to run the air conditioner and use the conditioned air.But how much would you want to run the air conditioner during a six hour charge? Would it turn into a 9 hour charge?I'm thinking that the i-MiEV's 3.3kW charger does not raise the battery temperature significantly during charging.However, the DC Quick Charger probably does raise the battery temperature significantly during charging, which is why the air conditioner is used to help cool the battery.I don't have much faith in the Mitsubishi dealers or Mitsubishi Motors North America, but I still hold out hope for the Mitsubishi engineers.

Even the Tesla Model S, with a liquid cooled battery, does not cool the battery when the vehicle isn't charging.If you're parked all day in 110 degree heat, then your battery is at 110 degrees all day.

Also, looking at Ben Nelson's videos on YouTube, it does look like there is separation for air flow in the i-MiEV's four and eight cell modules, so that each of the 88 cells has room to dissipate heat.

Finally, is there a way to tell what battery capacity loss there is with the i-MiEV?Can we tell by hooking up the Mitsubishi MUTIII tester?I have almost 18,000 miles on my i-MiEV and I am curious to know.

Cooling the battery in cars with the warming or QC option is pretty easy and I would have thought Mitsubishi would have figured it out. In my case with the leased car with the warming system all I did was disconnect the acutator at the floor duct and then move the arm so that the damper door in the duct would always divert air to the battery. When it is hot and you want to cool the battery, you can select where the air from the A/C system goes by turning the lower knob on the HVAC system from "face" to the "face/floor" position. This directs half of the air into the cabin and the other half into the battery. The A/C blower pushes the air through the battery pack and it exhausts though the battery pack fan (which isn't turning nor is it necessary) Using this method I can control the pack temperature while driving. The battery could also be heated in the winter using this same method by selecting "heat" from the HVAC, however usually battery heating is unnecessary and would be counterproductive based on the energy required to provide heat from the hot water heater vs. energy output gained from a warmer battery. The battery has a lot of mass, therefore the rise or fall of the temperature of the cells in the pack takes time. Any cooling you can provide while driving will keep the cell temperatures lower while parked then they would have gotten if you never cooled them in the first place. I put a temperature probe into the pack and using this method, I was able to get the air temperature in the battery enclosure down from over 100 degrees (on a 95 degree day) to below 75 degrees in just a few minutes. Thats not to say the cells themselves were at that temperature but at least they were able to disapate their heat by convection into the cooler air at a higher rate. For those of us who don't have the ductwork in the cars the final blow it that Mitsubishi will not sell you the parts necessary to modify the car to install the parts needed to do this. They do not service any components within or attached to the battery pack. They say (as all cars are still under warranty) they will handle any problems with in the pack and service it only as a single part under warranty. My question was what to do if I have accident damage or if I don't care about voiding my warranty what about selling me parts anyway. The answer was a not to polite NO.

siai47 wrote: The battery could also be heated in the winter using this same method by selecting "heat" from the HVAC, however usually battery heating is unnecessary and would be counterproductive based on the energy required to provide heat from the hot water heater vs. energy output gained from a warmer battery. The battery has a lot of mass, therefore the rise or fall of the temperature of the cells in the pack takes time.

I've read that in the winter, a best practice is to charge your battery before you need it so that the battery is warmed by the charging process versys charging the car when you get home and letting it sit all night cooling down. I'm thinking this goes with the thermal mass of the batteries.

I think you are onto something with this manually moving the door flap into the battery box. Too bad MMC won't sell you the parts but I think it's something you could do with a bit of HomeDepot engineering if like you said you don't care about the warranty. Some PVC plumbing parts is all you need. You may need to drop the pack but that guy that bought the flooded i-MiEV was able to get it down by himself. I have a motorcycle jack I bought from Canadian Tire on special for cheap that has a nice wide base for lifting bikes, if I ever need to drop my pack I plan on using that.

siai47 wrote:Cooling the battery in cars with the warming or QC option is pretty easy and I would have thought Mitsubishi would have figured it out. In my case with the leased car with the warming system all I did was disconnect the acutator at the floor duct and then move the arm so that the damper door in the duct would always divert air to the battery. When it is hot and you want to cool the battery, you can select where the air from the A/C system goes by turning the lower knob on the HVAC system from "face" to the "face/floor" position. This directs half of the air into the cabin and the other half into the battery. The A/C blower pushes the air through the battery pack and it exhausts though the battery pack fan (which isn't turning nor is it necessary) Using this method I can control the pack temperature while driving. The battery could also be heated in the winter using this same method by selecting "heat" from the HVAC, however usually battery heating is unnecessary and would be counterproductive based on the energy required to provide heat from the hot water heater vs. energy output gained from a warmer battery. The battery has a lot of mass, therefore the rise or fall of the temperature of the cells in the pack takes time. Any cooling you can provide while driving will keep the cell temperatures lower while parked then they would have gotten if you never cooled them in the first place. I put a temperature probe into the pack and using this method, I was able to get the air temperature in the battery enclosure down from over 100 degrees (on a 95 degree day) to below 75 degrees in just a few minutes. Thats not to say the cells themselves were at that temperature but at least they were able to disapate their heat by convection into the cooler air at a higher rate. For those of us who don't have the ductwork in the cars the final blow it that Mitsubishi will not sell you the parts necessary to modify the car to install the parts needed to do this. They do not service any components within or attached to the battery pack. They say (as all cars are still under warranty) they will handle any problems with in the pack and service it only as a single part under warranty. My question was what to do if I have accident damage or if I don't care about voiding my warranty what about selling me parts anyway. The answer was a not to polite NO.

Interesting project.How about using the remote at the start of charging to blow air conditioned air into the battery pack?

When I installed the factory speakers in the rear doors of my ES model, the guy at the parts counter looked up the part number and I ordered the speakers at http://www.ricartparts.com/. You could give it a try. The guy at ricart parts will even email you a drawing of the part that you are ordering to make sure it is the right one. My ES model has the warming option. My VIN # is JA3215H12CU015949 and the parts should come up for this vehicle. I too have the manuals for the i-MiEV. What parts to you need exactly?

It's possible you could use the remote to pre-cool the battery. However, I am not up to speed on the remote, but is seems the remote causes the A/C (or heat) system to default to some pre-configured operation. I don't know if it overrides the positions of the dash controls. As far as parts are concerned, some of the parts can be ordered from the dealer incuding the two ducts that are inside the passenger compartment. After that, nothing that is part of the traction battey pack is available. There are two pieces inside or on the pack that you need. One is the external boot that connects the ductwork to the top cover of the pack. The second item is a internal ductwork piece inside the pack to direct air to the various battery modules. I can see Mitsubishi's point about this as installing this stuff after the fact isn't for the faint of heart. There are also lethal voltages running around inside the pack to contend with. In the case of those with the QC or warming option, just removing the actuator and manually moving the damper lever gets you all the benefits you need for zero expense.

siai47 wrote:It's possible you could use the remote to pre-cool the battery. However, I am not up to speed on the remote, but is seems the remote causes the A/C (or heat) system to default to some pre-configured operation. I don't know if it overrides the positions of the dash controls. As far as parts are concerned, some of the parts can be ordered from the dealer incuding the two ducts that are inside the passenger compartment. After that, nothing that is part of the traction battey pack is available. There are two pieces inside or on the pack that you need. One is the external boot that connects the ductwork to the top cover of the pack. The second item is a internal ductwork piece inside the pack to direct air to the various battery modules. I can see Mitsubishi's point about this as installing this stuff after the fact isn't for the faint of heart. There are also lethal voltages running around inside the pack to contend with. In the case of those with the QC or warming option, just removing the actuator and manually moving the damper lever gets you all the benefits you need for zero expense.

I'll check how the remote cools the next time I charge to see if the cold air can be diverted to the battery.As for the two pieces inside or on the pack, you could make something to take the place of the external boot, and watch Ben Nelson's YouTube video for the ductwork. http://www.youtube.com/watch?v=EmgRuhqba0I You can get a good look at it at 3:48 in the video. I think that you could get effective cooling without it. If you push cold air in one end of the pack, then the hot air will be forced out the other end, and the coldest air will sink to the bottom. You wouldn't need to remove or work in the battery pack.